is a groove in a piece of wood that another piece of wood fits into. It has three sides, as opposed to a rabbEt's two sides.

Here is an example of a dado: Most furniture is based on a carcase, for example a bookcase. If you want adjustable shelves on a bookcase you drill holes in the vertical sides so you can put pins in for the shelf to sit on. But if you are going to have a shelf that stays in place, the best construction technique is to cut a dado in the vertical pieces and slide the shelf into the dado. You can fasten with glue or screws through the vertical into the end of the shelf. The "top shelf" (in actuality the top of the case would be dropped into a rabbet (which is just a dado without the third side.

I generally use a power router to make rabbets and dadoes, though you can also use a specialized plane called a plough to cut the groove. Some people even use a dovetail joint in place of a rabbet, but that's much harder to do because you have to slightly taper the rabbet so the shelf will slide into it easily. The taper might be only 0.2 mm in the entire length of the rabbet. That's too finicky for me. I generally measure to the nearest 1/64th of an inch (or about what half a mm?)

As an aside here, I find myself using the metric side of my tapes and rulers more and more because I find mms a bunch easier to deal with in my head than binary fractions.

TEd


TEd